Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions

International audience The vigor of the glacial Antarctic Circumpolar Current (ACC) and the locations of frontal boundaries are important parameters for understanding the role of the Southern Ocean in global climate change. Toward the goal of understanding the locations of currents we present a surv...

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Published in:Geochemistry, Geophysics, Geosystems
Main Authors: Hemming, S. R., van de Flierdt, T., Goldstein, S. L., Franzese, A. M., Roy, M., Gastineau, Guillaume, Landrot, G.
Other Authors: Lamont-Doherty Earth Observatory (LDEO), Columbia University New York, Department of Earth and Environmental Sciences New York, Département des Sciences de la Terre et de l'Atmosphère, Université du Québec à Montréal = University of Québec in Montréal (UQAM), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Plant and Soil Sciences, University of Delaware Newark
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2007
Subjects:
Online Access:https://hal.sorbonne-universite.fr/hal-01332216
https://hal.sorbonne-universite.fr/hal-01332216/document
https://hal.sorbonne-universite.fr/hal-01332216/file/Hemming_2007_Strontium_isotope.pdf
https://doi.org/10.1029/2006GC001441
id ftinsu:oai:HAL:hal-01332216v1
record_format openpolar
institution Open Polar
collection Institut national des sciences de l'Univers: HAL-INSU
op_collection_id ftinsu
language English
topic strontium isotopes
Antarctica
Antarctic Circumpolar Current
terrigenous sediments
provenance
neodymium isotopes
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
spellingShingle strontium isotopes
Antarctica
Antarctic Circumpolar Current
terrigenous sediments
provenance
neodymium isotopes
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Hemming, S. R.
van de Flierdt, T.
Goldstein, S. L.
Franzese, A. M.
Roy, M.
Gastineau, Guillaume
Landrot, G.
Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
topic_facet strontium isotopes
Antarctica
Antarctic Circumpolar Current
terrigenous sediments
provenance
neodymium isotopes
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
description International audience The vigor of the glacial Antarctic Circumpolar Current (ACC) and the locations of frontal boundaries are important parameters for understanding the role of the Southern Ocean in global climate change. Toward the goal of understanding the locations of currents we present a survey of Sr isotope ratios in terrigenous sediments around the perimeter of Antarctica. The pattern of the variations within the modern ACC is used to suggest that terrigenous sediment from Antarctica is injected into the ACC via the Ross and Weddell gyres in the south. North of the main ACC the Sr isotopes reflect continental contributions from Africa, Australia-New Zealand, and South America. Along a transect northward from the Ross Sea, Sr isotope ratios show a decrease from higher values in the south (Antarctic provenance) to lower values in the north (provenance from New Zealand). This otherwise monotonic decrease is interrupted within the ACC by a ''zigzag'' to lower and then higher values, which accompanies minimum terrigenous flux. This zigzag requires contributions from two additional sediment sources beyond the main Antarctic and New Zealand end-members. The lower Sr isotope ratios are attributable to greater contributions from basaltic sources within the current, a consistent pattern around the ACC. The samples with higher Sr isotope ratios point to an additional contributor, possibly a wind-transported component from Australia. During the LGM there is a systematic geographical variation in the Sr isotope ratios, similar to that of the Holocene. A small offset of the zigzag to the north (approximately 1°–2°) may indicate a small northward shift of the southern boundary of the ACC. More highly resolved data are required to test whether this northward shift is really significant and whether it applies to other ACC fronts during the LGM.
author2 Lamont-Doherty Earth Observatory (LDEO)
Columbia University New York
Department of Earth and Environmental Sciences New York
Département des Sciences de la Terre et de l'Atmosphère
Université du Québec à Montréal = University of Québec in Montréal (UQAM)
Laboratoire de Météorologie Dynamique (UMR 8539) (LMD)
Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris
École normale supérieure - Paris (ENS-PSL)
Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL)
Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Department of Plant and Soil Sciences
University of Delaware Newark
format Article in Journal/Newspaper
author Hemming, S. R.
van de Flierdt, T.
Goldstein, S. L.
Franzese, A. M.
Roy, M.
Gastineau, Guillaume
Landrot, G.
author_facet Hemming, S. R.
van de Flierdt, T.
Goldstein, S. L.
Franzese, A. M.
Roy, M.
Gastineau, Guillaume
Landrot, G.
author_sort Hemming, S. R.
title Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
title_short Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
title_full Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
title_fullStr Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
title_full_unstemmed Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions
title_sort strontium isotope tracing of terrigenous sediment dispersal in the antarctic circumpolar current: implications for constraining frontal positions
publisher HAL CCSD
publishDate 2007
url https://hal.sorbonne-universite.fr/hal-01332216
https://hal.sorbonne-universite.fr/hal-01332216/document
https://hal.sorbonne-universite.fr/hal-01332216/file/Hemming_2007_Strontium_isotope.pdf
https://doi.org/10.1029/2006GC001441
geographic Antarctic
New Zealand
Ross Sea
Southern Ocean
The Antarctic
Weddell
geographic_facet Antarctic
New Zealand
Ross Sea
Southern Ocean
The Antarctic
Weddell
genre Antarc*
Antarctic
Antarctica
Ross Sea
Southern Ocean
genre_facet Antarc*
Antarctic
Antarctica
Ross Sea
Southern Ocean
op_source ISSN: 1525-2027
EISSN: 1525-2027
Geochemistry, Geophysics, Geosystems
https://hal.sorbonne-universite.fr/hal-01332216
Geochemistry, Geophysics, Geosystems, 2007, 8 (6), ⟨10.1029/2006GC001441⟩
op_relation info:eu-repo/semantics/altIdentifier/doi/10.1029/2006GC001441
hal-01332216
https://hal.sorbonne-universite.fr/hal-01332216
https://hal.sorbonne-universite.fr/hal-01332216/document
https://hal.sorbonne-universite.fr/hal-01332216/file/Hemming_2007_Strontium_isotope.pdf
doi:10.1029/2006GC001441
op_rights info:eu-repo/semantics/OpenAccess
op_doi https://doi.org/10.1029/2006GC001441
container_title Geochemistry, Geophysics, Geosystems
container_volume 8
container_issue 6
container_start_page n/a
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spelling ftinsu:oai:HAL:hal-01332216v1 2023-11-12T04:05:59+01:00 Strontium isotope tracing of terrigenous sediment dispersal in the Antarctic Circumpolar Current: Implications for constraining frontal positions Hemming, S. R. van de Flierdt, T. Goldstein, S. L. Franzese, A. M. Roy, M. Gastineau, Guillaume Landrot, G. Lamont-Doherty Earth Observatory (LDEO) Columbia University New York Department of Earth and Environmental Sciences New York Département des Sciences de la Terre et de l'Atmosphère Université du Québec à Montréal = University of Québec in Montréal (UQAM) Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) Department of Plant and Soil Sciences University of Delaware Newark 2007 https://hal.sorbonne-universite.fr/hal-01332216 https://hal.sorbonne-universite.fr/hal-01332216/document https://hal.sorbonne-universite.fr/hal-01332216/file/Hemming_2007_Strontium_isotope.pdf https://doi.org/10.1029/2006GC001441 en eng HAL CCSD AGU and the Geochemical Society info:eu-repo/semantics/altIdentifier/doi/10.1029/2006GC001441 hal-01332216 https://hal.sorbonne-universite.fr/hal-01332216 https://hal.sorbonne-universite.fr/hal-01332216/document https://hal.sorbonne-universite.fr/hal-01332216/file/Hemming_2007_Strontium_isotope.pdf doi:10.1029/2006GC001441 info:eu-repo/semantics/OpenAccess ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://hal.sorbonne-universite.fr/hal-01332216 Geochemistry, Geophysics, Geosystems, 2007, 8 (6), ⟨10.1029/2006GC001441⟩ strontium isotopes Antarctica Antarctic Circumpolar Current terrigenous sediments provenance neodymium isotopes [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2007 ftinsu https://doi.org/10.1029/2006GC001441 2023-11-01T17:27:45Z International audience The vigor of the glacial Antarctic Circumpolar Current (ACC) and the locations of frontal boundaries are important parameters for understanding the role of the Southern Ocean in global climate change. Toward the goal of understanding the locations of currents we present a survey of Sr isotope ratios in terrigenous sediments around the perimeter of Antarctica. The pattern of the variations within the modern ACC is used to suggest that terrigenous sediment from Antarctica is injected into the ACC via the Ross and Weddell gyres in the south. North of the main ACC the Sr isotopes reflect continental contributions from Africa, Australia-New Zealand, and South America. Along a transect northward from the Ross Sea, Sr isotope ratios show a decrease from higher values in the south (Antarctic provenance) to lower values in the north (provenance from New Zealand). This otherwise monotonic decrease is interrupted within the ACC by a ''zigzag'' to lower and then higher values, which accompanies minimum terrigenous flux. This zigzag requires contributions from two additional sediment sources beyond the main Antarctic and New Zealand end-members. The lower Sr isotope ratios are attributable to greater contributions from basaltic sources within the current, a consistent pattern around the ACC. The samples with higher Sr isotope ratios point to an additional contributor, possibly a wind-transported component from Australia. During the LGM there is a systematic geographical variation in the Sr isotope ratios, similar to that of the Holocene. A small offset of the zigzag to the north (approximately 1°–2°) may indicate a small northward shift of the southern boundary of the ACC. More highly resolved data are required to test whether this northward shift is really significant and whether it applies to other ACC fronts during the LGM. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ross Sea Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Antarctic New Zealand Ross Sea Southern Ocean The Antarctic Weddell Geochemistry, Geophysics, Geosystems 8 6 n/a n/a